建立定量描述阻燃钛合金抗点燃性能的摩擦接触压力P与预混气流氧浓度c₀关系, 对比研究Ti-V-Cr系阻燃钛合金及常规钛合金的抗点燃性能, 并基于摩擦生热原理和着火热爆燃理论对阻燃钛合金的抗点燃机理进行模型计算分析. 结果表明, 当c₀≥70%时, Ti40钛合金在室温下即会点燃. Ti40钛合金的抗点燃性能比Alloy C⁺钛合金低2.5%, 比TC4钛合金高40%. 阻燃钛合金的着火源为摩擦过程产生的微凸体, 氧的化学吸附是氧与微凸体相互作用的控制步骤, 阻燃钛合金的摩擦点燃临界温度T ^*随等效压力P_eq的增大而减小. 对于Ti40钛合金, 当P_eq在0.1~0.5 MPa变化时, T^*的变化范围为1073~1323 K; 摩擦表面由TiO₂, V₂O₅和Cr₂O₃等氧化物融合物构成, 厚度为2~5ηm. 摩擦过程中该层融合物改善了接触表面的润滑条件, 使摩擦区的温度大幅度降低, 从而提高了阻燃钛合金的抗点燃性能.

As a type of structure functional high temperature alloy, the ignition resistance performance of fireproof titanium alloy is an important basis for the safety in the application. In this work, the relationship between the friction contact pressure P and oxygen concentration c₀ of mixed airflow was established to describe the ignition resistance of fireproof titanium alloys. The ignition resistance of the traditional titanium alloys and typical Ti-V-Cr type titanium alloys was investigated and compared. Based on the principle of friction-induced heat and the thermal explosion theory of ignition, the mechanism of the ignition resistance of fireproof titanium alloys was modeled, calculated and analyzed. The results showed that Ti40 was ignited immediately at room temperature as c₀≥70%. The ignition resistance of Ti40 was 2.5% lower than that of Alloy C⁺ and 40% higher than that of TC4. The ignition originated from the micro-tip formed during friction and the chemical adsorption of oxygen on the micro-tip was the key step for the interaction. With increasing of equivalent pressure P_eq, the critical temperature T ^* ignited by friction decreasd. When P_eq varied from 0.1 to 0.5 MPa, T ^* of Ti40 ranged from 1073 to 1323 K. The surface under friction was 2~5 μm and composed of the fusion of the oxides including TiO₂, V₂O₅ and Cr₂O₃. The lubrication condition between the contacting surfaces was improved by the fused layer and resulted in great temperature decrease in the friction area. Consequently, the ignition resistance of fireproof titanium alloys was improved.